• at P8, mutant brains display notable inward depressions in both hemispheres of the cortical mantel, extending from the somatosensory cortex to the parietal associated cortex, auditory cortex and visual cortex

• a 1.75- and 1.4-fold increase in neuronal density is observed in cortical layer V and II, respectively, relative to controls; however, the thickness of cortical layer I, which contains axons from pyramidal neurons, is normal

• within cortical layer V, mutant cell bodies appear shrunken and show a 37% decrease in cross sectional area relative to controls